The present invention is suitable for use in the fabrication of LCDs, backlight displays, backlight plate of slices, advertisement billboards and the other devices with a backlight source device.
With the improvement of technology, LCDs, backlight displays, backlight plate of slices, advertisement billboard and the other devices using a backlight source device must be used widely, and thus a backlight source device with improved uniform illumination is eagerly demanded.
A light guide plate 1 in the prior art is shown in FIG. 1, which produces a printing pattern of a light guiding plate 1 of a lateral light source 11. The pattern is formed by a plurality of trenches or convex strips, or matrix points, and other diffusion units, or a plurality of parallel trenches with equal spaces and depths for diffusing and reflecting light of a lateral light source.
The defects of the prior art backlight source device is that in printing, the useability of the light of the front face is relatively low. Since the angles of all the diffusion units can not be changed, the output direction of the diffusing light can not be controlled.
For example, for straight parallel trenches on the light guide plate of a backlight source device, a non-uniform light strip will be formed. The light reflected from the area near the middle of the radiating area of the lateral light source 11 is stronger than that farther from the middle, and trenches with equal space and depth can cause that the emitted light are to be distributed non-uniformly.
It is difficult to control the output angle of the output light from the light guide plate of a backlight source device, especially in the two sides of the diffusion unit 12. In the place near the two sides of the diffusion units, the angle formed by the line between the lateral light source and the diffusion unit and the parallel lines of the diffusion units can not form a vertical projection so that the angle of light output can not be well controlled.